In seat belt systems for vehicles, it is often desirable to be able to anchor the seat belt at one of its anchor points to a stud that is fixed to the seat frame near the floor of the vehicle. In some instances, seat belt systems may be installed after the vehicle seats are finished or partially finished, so that it is difficult to give a clear view of the anchor stud. For example, the anchor may have to be fit through an opening or gap between the plastic trim of the seat and the seat frame member to which the stud is affixed. It may also be the case that the anchor has to be fit between a small opening formed in the upholstery for being lowered down to the lower stud via a fishing installation tool and then connected to the stud.
One such device for this purpose is disclosed in PCT Publication, WO 01/42063A1 ('063 publication). In the '063 publication, a keyhole opening is formed in a plate member adjacent to a seat belt opening. The stud head is fit through the enlarged portion of the keyhole opening and then slid down toward the opposite end of the narrow, slot portion of the keyhole opening. A spring retainer connected to the plate member is operable to keep the member fixed in an installed position with the stud head at the distal end of the slot portion of the keyhole opening.
However, the '063 anchor device has several shortcomings. One problem lies in the manner in which the spring retainer is secured to the plate member. The retainer is secured by two distinct rivets spaced across the enlarged portion of the keyhole opening so that the device disclosed in the '063 publication has four distinct components including the plate member, the spring retainer member, and each of the two rivets. In addition to increasing part costs, there are two separate riveting operations that need be performed to attach the spring retainer to the plate member thus increasing assembly time and cost accordingly.
In addition, during the fitting of the stud head through the keyhole opening, it can be difficult for the installer to be able to know when the stud head has been properly aligned with the keyhole opening for this procedure. This is because the portion of the spring retainer extending above the enlarged portion of the keyhole opening is spaced from the plate member by a distance greater than the thickness of the stud head so that the retainer provides no resistance to moving of the stud head through this enlarged opening portion. Further, because of this spacing once the stud head engages the spring retainer, the installer typically will then want to carefully reposition the stud head closer to the plate for moving the stud to the installed position. Without repositioning the plate so that the stud head is closer thereto, upward pulling on the plate will generate large forces resisting this movement by the spring retainer and the retainer arms thereof making installation more difficult than is desired.
Other problems include space constraints that may be present during installation that can make it difficult to properly align the plate member and stud for fitting the stud head through the key hole opening. Further, after installation, it is desirable for the anchor device to stay securely mounted to the stud during vehicle impacts that generate transverse separation forces between the stud head and spring retainer, such as certain vehicle side impacts may generate.